Search results for: buffer zones

Authors: Ziya Esen, Özgür Duygulu, Nazlı S. Büyükatak

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This study investigates the effects of aging heat treatment on corrosion resistance and mechanical properties of WE43 Magnesium alloy. The heat treatment of alloys was conducted by solutionizing at 525oC for 16 h, followed by aging at 190, 210 and 230oC for up to 48 h. The type and the size of precipitates formed upon aging have influenced both the mechanical properties and corrosion behavior of the alloy. Solutionized alloy displayed the worst corrosion resistance in simulated body fluid, while peak hardness and the best corrosion resistance were observed in the alloy aged at 210oC for 24 h as a result of β’ precipitate formation. Longer aging duration at 210oC decreased the corrosion rate due to the coarsening of the precipitates and formation of precipitate-free zones. The increased corrosion resistance of the peak aged samples was attributed to the slowing down effect of the Mg(OH)₂/MgO corrosion layer by the pinning effect of β’-precipitates.

Keywords: WE43 magnesium alloy, simulated body fluid, corrosion, mechanical properties

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Authors: Ambreen Aslam, Tahira Aziz Mughal, Skye R. Thomas-Hall, Peer M. Schenk

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Biodiesel is an alternative to petroleum-derived fuel mainly composed of fatty acid from oleaginous microalgae feedstock. Microalgae produced fatty acid methyl esters (FAMEs) as they can store high levels of lipids without competing for food productivity. After lipid extraction and esterification, fatty acid profile from algae feedstock possessed the abundance of fatty acids with carbon chain length specifically C16 and C18. The qualitative analysis of FAME was done by cultivating mix microalgae consortia under three different CO₂ concentrations (1%, 3%, and 5.5%) from a coal fired flue gas. FAME content (280.3 µg/mL) and productivity (18.69 µg/mL/D) was higher under 1% CO₂ (flue gas) as compare to other treatments. Whereas, Mixed C. (F) supplemented with 5.5% CO₂ (50% flue gas) had higher SFA (36.28%) and UFA (63.72%) which improve the oxidative stability of biodiesel. Subsequently, low Iodine value (136.3 gI₂/100g) and higher Cetane number (52) of Mixed C.+P (F) were found to be in accordance with European (EN 14214) standard under 5.5% CO₂ along with 50mM phosphate buffer. Experimental results revealed that sufficient phosphate reduced FAME productivity but significantly enhance biodiesel quality. This research aimed to develop an integrated approach of utilizing flue gas (as CO₂ source) for significant improvement in biodiesel quality under surplus phosphorus. CO₂ sequestration from industrial flue gas not only reduce greenhouse gases (GHG) emissions but also ensure sustainability and eco-friendliness of the biodiesel production process through microalgae.

Keywords: biodiesel analysis, carbon dioxide, coal fired flue gas, FAME productivity, fatty acid profile, fuel properties, lipid content, mixed culture microalgae

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Authors: Hefzollah Mohammadian, Ensieh Hajeb, Mohamad Baqer Heidari

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In this paper, for the protection and safety of tanks gases (flammable materials) and also due to the considerable economic value of the reservoir, the new system for the protection, the conservation and fire fighting has been cloned. The system consists of several parts: the Sensors to detect heat and fire with Nanotechnology (nano sensor), Barrier for isolation and protection from a range of two electronic zones, analyzer for detection and locating point of fire accurately, Main electronic board to announce fire, Fault diagnosis in different locations, such as relevant alarms and activate different devices for fire distinguish and announcement. An important feature of this system, high speed and capability of fire detection system in a way that is able to detect the value of the ambient temperature that can be adjusted. Another advantage of this system is autonomous and does not require human operator in place. Using nanotechnology, in addition to speeding up the work, reduces the cost of construction of the sensor and also the notification system and fire extinguish.

Keywords: analyser, barrier, heat resistance, general fault, general alarm, nano sensor

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Authors: Dominic Sagar

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Manchester ‘King Cotton’, the first truly industrial city of the nineteenth century, passing on the baton to Detroit ‘Motor City’, is the first truly modern city. We are exploring the tales of the two cities, their rise and fall and subsequent post-industrial decline, their transitions and transformations, whilst alongside paralleling their corresponding, commercial, cultural, industrial and even agricultural, artistic and musical transactions and connections. The paper will briefly contextualize how technologies of the industrial age and modern age have been instrumental in the development of these cities and other similar cities including New York. However, the main focus of the study will be the present and more importantly the future, how globalisation and the advancements of digital technologies and industries have shaped the cities developments from AlanTuring and the making of the first programmable computer to the effect of digitalisation and digital initiatives. Manchester now has a thriving creative digital infrastructure of Digilabs, FabLabs, MadLabs and hubs, the study will reference the Smart Project and the Manchester Digital Development Association whilst paralleling similar digital and creative industrial initiatives now starting to happen in Detroit. The paper will explore other topics including the need to allow for zones of experimentation, areas to play, think and create in order develop and instigate new initiatives and ideas of production, carrying on the tradition of influential inventions throughout the history of these key cities. Other topics will be briefly touched on, such as urban farming, citing the Biospheric foundation in Manchester and other similar projects in Detroit. However, the main thread will focus on the music industries and how they are contributing to the regeneration of cities. Musically and artistically, Manchester and Detroit have been closely connected by the flow and transmission of information and transfer of ideas via ‘cars and trains and boats and planes’ through to the new ‘super highway’. From Detroit to Manchester often via New York and Liverpool and back again, these musical and artistic connections and flows have greatly affected and influenced both cities and the advancement of technology are still connecting the cities. In summary two hugely important industrial cities, subsequently both experienced massive decline in fortunes, having had their large industrial hearts ripped out, ravaged leaving dying industrial carcasses and car crashes of despair, dereliction, desolation and post-industrial wastelands vacated by a massive exodus of the cities’ inhabitants. To examine the affinity, similarity and differences between Manchester & Detroit, from their industrial importance to their post-industrial decline and their current transmutations, transformations, transient transgressions, cities in transition; contrasting how they have dealt with these problems and how they can learn from each other. With a view to framing these topics with regard to how various communities have shaped these cities and the creative industries and design [the new cotton/car manufacturing industries] are reinventing post-industrial cities, to speculate on future development of these themes in relation to Globalisation, digitalisation and how cities can function to develop solutions to communal living in cities of the future.

Keywords: cultural capital, digital developments, musical initiatives, zones of experimentation

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Authors: Ren Moses, Emmanuel Kidando, Eren Ozguven, Yassir Abdelrazig

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Although older drivers (defined as those of age 65 and above) are less involved with speeding, alcohol use as well as night driving, they are more vulnerable to severe crashes. The major contributing factors for severe crashes include frailty and medical complications. Several studies have evaluated the contributing factors on severity of crashes. However, few studies have established the impact of travel time reliability (TTR) on road safety. In particular, the impact of TTR on senior adults who face several challenges including hearing difficulties, decreasing of the processing skills and cognitive problems in driving is not well established. Therefore, this study focuses on determining possible impacts of TTR on the traffic safety with focus on elderly drivers. Historical travel speed data from freeway links in the study area were used to calculate travel time and the associated TTR metrics that is, planning time index, the buffer index, the standard deviation of the travel time and the probability of congestion. Four-year information on crashes occurring on these freeway links was acquired. The binary logit model estimated using the Markov Chain Monte Carlo (MCMC) sampling technique was used to evaluate variables that could be influencing elderly crash severity. Preliminary results of the analysis suggest that TTR is statistically significant in affecting the severity of a crash involving an elderly driver. The result suggests that one unit increase in the probability of congestion reduces the likelihood of the elderly severe crash by nearly 22%. These findings will enhance the understanding of TTR and its impact on the elderly crash severity.

Keywords: highway safety, travel time reliability, elderly drivers, traffic modeling

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Authors: Taoufik Benchelha, Toufik Remmal, Rachid El Hamdouni, Hamou Mansouri, Houssein Ejjaouani, Halima Jounaid, Said Benchelha

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During the earthworks for the construction of Marrakech-Agadir highway in southern Morocco, which crosses mountainous areas of the High Western Atlas, the main problem faced is the stability of the slopes. Indeed, the use of explosives as a means of excavation associated with the geological structure of the terrain encountered can trigger major ruptures and cause damage which depends on the intrinsic characteristics of the rock mass. The study consists of a geological and geotechnical analysis of several unstable zones located along the route, mobilizing millions of cubic meters of rock, with deduction of the parameters influencing slope stability. From this analysis, a predictive model for rock mass stability is carried out, based on a statistic method of logistic regression, in order to predict the geomechanical behavior of the rock slopes constrained by earthworks.

Keywords: explosive, logistic regression, rock mass, slope stability

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Authors: Asavasereerat K., Teacharsripaitoon T., Tungyingyong P., Charupongrat S., Noppiboon S. Hochareon L., Kitsuban P.

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Third generation of vaccines is based on gene therapy where DNA is introduced into patients. The antigenic or therapeutic proteins encoded from transgenes DNA triggers an immune-response to counteract various diseases. Moreover, DNA vaccine offers the customization of its ability on protection and treatment with high stability. The production of DNA vaccines become of interest. According to USFDA guidance for industry, the recommended limits for impurities from host cell are lower than 1%, and the active conformation homogeneity supercoiled DNA, is more than 80%. Thus, the purification strategy using two-steps chromatography has been established and verified for its robustness. Herein, pVax1/lacZ, a pre-approved USFDA DNA vaccine backbone, was used and transformed into E. coli strain DH5α. Three purification process parameters including sample-loading flow rate, the salt concentration in washing and eluting buffer, were studied and the experiment was designed using response surface method with central composite face-centered (CCF) as a model. The designed range of selected parameters was 10% variation from the optimized set point as a safety factor. The purity in the percentage of supercoiled conformation obtained from each chromatography step, AIEX and HIC, were analyzed by HPLC. The response data were used to establish regression model and statistically analyzed followed by Monte Carlo simulation using SAS JMP. The results on the purity of the product obtained from AIEX and HIC are between 89.4 to 92.5% and 88.3 to 100.0%, respectively. Monte Carlo simulation showed that the pVAX1/lacZ purification process is robust with confidence intervals of 0.90 in range of 90.18-91.00% and 95.88-100.00%, for AIEX and HIC respectively.

Keywords: AIEX, DNA vaccine, HIC, puification, response surface method, robustness

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Authors: Erkihun Zelalem

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Ethiopian’s sheep population, estimated to be 25.5 million heads, is found widely distributed across the diverse agro-ecological zones of the country. In the past, there were many projects that done to improve production of meat, milk and productivity of sheep breed. However, no significance research has been done so far on production of wool fiber in Ethiopia which could be taken as a potential fiber next to cotton. The measurement of the sheep wool fiber physical properties is critically important, technical, commercial and certification point of view. A total of 24 sheep from different breeds (Menz, Tikur, Farta and Washera) were used in this study. Samples of fiber were analyzed using standard measurements for wool fiber length (WFL), mean fiber diameter (MFD), coefficient of variation of wool fiber diameter (FDCV), breaking strength, elongation, crimp, cleanness and moisture content. Based on the result all parameters shows that there is a great potential of getting of wool fiber from the skin of sheep and according to the standards of its property and grading system based on wool fiber fineness is medium to course. These types of fibers can be making carpets, blankets, rugs, coverings and other products.

Keywords: Fiber, Fineness, Carpet, Fleece, Raw Wool

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Authors: Abdelghani Qadem, Zouhair Qadem

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Like the countries of the Mediterranean region, Morocco is likely to be at high risk of water scarcity due to climate change. Morocco, which is the subject of this study, is located between two climatic zones, temperate in the North tropical in the South, Morocco is distinguished by four types of climate: humid, sub-humid, semi-arid, and arid. The last decades attest to the progression of the semi-arid climate towards the North of the country. The IPCC projections, which have been made in this direction, show that there is an overall downward trend in rainfall contributions varying on average between 10% and 30% depending on the scenario selected and the region considered, they also show an upward trend in average annual temperatures. These trends will have a real impact on water resources, which will result in a drop in the volume of water resources varying between 7.6% and 40.6%. The present study aims to describe the meteorological conditions of Morocco in order to answer the problem dealing with the effect of climatic fluctuations on water resources and to assess water vulnerability in the face of climate change.

Keywords: morocco, climate change, water resources, impact, water scarcity

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Authors: Nima Shafaghi, Gunay Anlaş, C. Can Aydiner

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A realistic understanding of martensitic phase transition under complex stress states is key for accurately describing the mechanical behavior of shape memory alloys (SMAs). Particularly regarding the sharply changing stress fields at the tip of a crack, the size, nature and shape of transformed zones are of great interest. There is significant variation among various analytical models in their predictions of the size and shape of the transformation zone. As the fully transformed region remains inside a very small boundary at the tip of the crack, experimental validation requires microscopic resolution. Here, the crack tip vicinity of NiTi compact tension specimen has been monitored in situ with microscopic image correlation with 20x magnification. With nominal 15 micrometer grains and 0.2 micrometer per pixel optical resolution, the strains at the crack tip are mapped with intra-grain detail. The transformation regions are then deduced using an equivalent strain formulation.

Keywords: digital image correlation, fracture, martensitic phase transition, mode I, NiTi, transformation zone

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Authors: Wilman Septina, Rajiv R. Prabhakar, Thomas Moehl, David Tilley

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Cupric oxide (CuO) is a promising absorber material for the fabrication of scalable, low cost solar energy conversion devices, due to the high abundance and low toxicity of copper. It is a p-type semiconductor with a band gap of around 1.5 eV, absorbing a significant portion of the solar spectrum. One of the main challenges in using CuO as solar absorber in an aqueous system is its tendency towards photocorrosion, generating Cu2O and metallic Cu. Although there have been several reports of CuO as a photocathode for hydrogen production, it is unclear how much of the observed current actually corresponds to H2 evolution, as the inevitability of photocorrosion is usually not addressed. In this research, we investigated the effect of the deposition of overlayers onto CuO thin films for the purpose of enhancing its photostability as well as performance for water splitting applications. CuO thin film was fabricated by galvanic electrodeposition of metallic copper onto gold-coated FTO substrates, followed by annealing in air at 600 °C. Photoelectrochemical measurement of the bare CuO film using 1 M phosphate buffer (pH 6.9) under simulated AM 1.5 sunlight showed a current density of ca. 1.5 mA cm-2 (at 0.4 VRHE), which photocorroded to Cu metal upon prolonged illumination. This photocorrosion could be suppressed by deposition of 50 nm-thick TiO2, deposited by atomic layer deposition. In addition, we found that insertion of an n-type CdS layer, deposited by chemical bath deposition, between the CuO and TiO2 layers was able to enhance significantly the photocurrent compared to without the CdS layer. A photocurrent of over 2 mA cm-2 (at 0 VRHE) was observed using the photocathode stack FTO/Au/CuO/CdS/TiO2/Pt. Structural, electrochemical, and photostability characterizations of the photocathode as well as results on various overlayers will be presented.

Keywords: CuO, hydrogen, photoelectrochemical, photostability, water splitting

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Authors: Raed H. Allawi

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Formation pressure is the most critical parameter in hydrocarbon exploration and exploitation. Specifically, predicting abnormal pressures (high formation pressures) and subnormal pressure zones can provide valuable information to minimize uncertainty for anticipated drilling challenges and risks. This study aims to interpret and delineate the pore and fracture pressure of the Mishrif reservoir in the southern Iraq Oilfield. The data required to implement this study included acoustic compression wave, gamma-ray, bulk density, and drilling events. Furthermore, supporting these models needs the pore pressure measurement from the Modular Formation Dynamics Tester (MDT). Many measured values of pore pressure were used to validate the accurate model. Using sonic velocity approaches, the mean absolute percentage error (MAPE) was about 4%. The fracture pressure results were consistent with the measurement data, actual drilling report, and events. The model's results will be a guide for successful drilling in future wells in the same oilfield.

Keywords: pore pressure, fracture pressure, overburden pressure, effective stress, drilling events

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Authors: Sukanya Devi Ramachandran, Vaishnavi Muralidharan, Kavya Chandrasekaran

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Polycaprolactone is polymer belonging to the polyester family that has noticeable characteristics of biodegradability and biocompatibility which is essential for medical applications. Polycaprolactone is produced by the ring opening polymerization of the monomer epsilon-Caprolactone (ε-CL) which is a closed ester, comprising of seven-membered ring. This process is normally catalysed by metallic components such as stannous octoate. It is difficult to remove the catalysts after the reaction, and they are also toxic to the human body. An alternate route of using enzymes as catalysts is being employed to reduce the toxicity. Lipase enzyme is a subclass of esterase that can easily attack the ester bonds of ε-CL. This research paper throws light on the extraction of lipase from germinating sunflower seeds and the activity of the biocatalyst in the polymerization of ε-CL. Germinating Sunflower seeds were crushed with fine sand in phosphate buffer of pH 6.5 into a fine paste which was centrifuged at 5000rpm for 10 minutes. The clear solution of the enzyme was tested for activity at various pH ranging from 5 to 7 and temperature ranging from 40oC to 70oC. The enzyme was active at pH6.0 and at 600C temperature. Polymerization of ε-CL was done using toluene as solvent with the catalysis of lipase enzyme, after which chloroform was added to terminate the reaction and was washed in cold methanol to obtain the polymer. The polymerization was done by varying the time from 72 hours to 6 days and tested for the molecular weight and the conversion of the monomer. The molecular weight obtained at 6 days is comparably higher. This method will be very effective, economical and eco-friendly to produce as the enzyme used can be regenerated as such at the end of the reaction and can be reused. The obtained polymers can be used for drug delivery and other medical applications.

Keywords: lipase, monomer, polycaprolactone, polymerization

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Authors: Nabamita Nath, Sanghamitra Sarkar

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Urban development in traditional neighbourhoods of cities is undergoing a sea change due to imposition of irregular development patterns on a predominantly inclusive urban fabric. In recent times, traditional neighbourhoods of Kolkata have experienced irregular urban development which has resulted in transformation of its immediate urban character. The goal is to study and analyse impact of new urban developments within traditional neighbourhoods of Kolkata and establish development guidelines to balance the old with the new. Various cities predominantly in third world countries are also experiencing similar development patterns in their traditional neighbourhoods. Existing literature surveys of development patterns in such neighbourhoods have established 9 major parameters viz. edge, movement, node, landmark, size-density, pattern-grain-texture, open spaces, urban spaces, urban form and views-vistas of the neighbourhood. To evaluate impact of urban development in traditional neighbourhoods of Kolkata, 3 different areas have been chronologically selected based on their settlement patterns. Parameters established through literature surveys have been applied to the selected areas to study and analyse the existing patterns of development. The main sources of this study included extensive on-site surveys, academic archive, census data, organisational records and informational websites. Applying the established parameters, 5 major conclusions were derived. Firstly, it was found that pedestrian friendly neighbourhoods of the city were becoming more car-centric. This has resulted in loss of interactive and social spaces which defined the cultural heritage of Kolkata. Secondly, the urban pattern which was composed of dense and compact fabric is gradually losing its character due to incorporation of new building typologies. Thirdly, the new building typologies include gated communities with private open spaces which is a stark departure from the existing built typology. However, these open spaces have not contributed in creation of inclusive public places for the community which are a significant part of such heritage neighbourhood precincts. Fourthly, commercial zones that primarily developed along major access routes have now infiltrated within these neighbourhoods. Gated communities do not favour formation of on-street commercial activities generating haphazard development patterns. Lastly, individual residential buildings that reflected Indo-saracenic and Neo-gothic architectural styles are converting into multi-storeyed residential apartments. As a result, the axis that created a definite visual identity for a neighbourhood is progressively following an irregular pattern. Thus, uniformity of the old skyline is gradually becoming inconsistent. The major issue currently is threat caused by irregular urban development to heritage zones and buildings of traditional neighbourhoods. Streets, lanes, courtyards, open spaces and buildings of old neighbourhoods imparted a unique cultural identity to the city that is disappearing with emerging urban development patterns. It has been concluded that specific guidelines for urban development should be regulated primarily based on existing urban form of traditional neighbourhoods. Such neighbourhood development strategies should be formulated for various cities of third world countries to control irregular developments thereby balancing heritage and development.

Keywords: heritage, Kolkata, traditional neighbourhood, urban development

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Authors: R. Charoen, S. Tipkanon, W. Savedboworn, N. Phonsatta, A. Panya

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Rice bran protein hydrolysates (RBPH) were prepared from defatted rice bran of two different Thai rice cultivars (Plai-Ngahm-Prachinburi; PNP and Khao Dok Mali 105; KDM105) using an enzymatic method. This research aimed to optimize enzyme-assisted protein extraction. In addition, the functional properties of RBPH and their stabilities to environmental stresses including pH (3 to 8), ionic strength (0 mM to 500 mM) and the thermal treatment (30 °C to 90 °C) were investigated. Results showed that enzymatic process for protein extraction of defatted rice bran was as follows: enzyme concentration 0.075 g/ 5 g of protein, extraction temperature 50 °C and extraction time 4 h. The obtained protein hydrolysate powders had a degree of hydrolysis (%) of 21.05% in PNP and 19.92% in KDM105. The solubility of protein hydrolysates at pH 4-6 was ranged from 27.28-38.57% and 27.60-43.00% in PNP and KDM105, respectively. In general, antioxidant activities indicated by total phenolic content, FRAP, ferrous ion-chelating (FIC), and 2,2’-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) of KDM105 had higher than PNP. In terms of functional properties, the emulsifying activity index (EAI) was was 8.78 m²/g protein in KDM105, whereas PNP was 5.05 m²/g protein. The foaming capacity at 5 minutes (%) was 47.33 and 52.98 in PNP and KDM105, respectively. Glutamine, Alanine, Valine, and Leucine are the major amino acid in protein hydrolysates where the total amino acid of KDM105 gave higher than PNP. Furthermore, we investigated environmental stresses on the stability of 5% oil in water emulsion (5% oil, 10 mM citrate buffer) stabilized by RBPH (3.5%). The droplet diameter of emulsion stabilized by KDM105 was smaller (d < 250 nm) than produced by PNP. For environmental stresses, RBPH stabilized emulsions were stable at pH around 3 and 5-6, at high salt (< 400 mM, pH 7) and at temperatures range between 30-50°C.

Keywords: functional properties, oil in water emulsion, protein hydrolysates, rice bran protein

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Authors: Yifan Gao

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Owing to the high breakdown field, high saturation drift velocity, 2DEG with high density and mobility and so on, AlGaN/GaN HEMTs have been widely used in high-frequency and high-power applications. To acquire a higher power often means higher breakdown voltage and higher drain current. Surface leakage current is usually the key issue affecting the breakdown voltage and power performance. In this work, we have performed in-situ N₂/NH₃ pretreatment before the passivation to suppress the surface leakage and achieve device performance enhancement. The AlGaN/GaN HEMT used in this work was grown on a 3-in. SiC substrate, whose epitaxial structure consists of a 3.5-nm GaN cap layer, a 25-nm Al₀.₂₅GaN barrier layer, a 1-nm AlN layer, a 400-nm i-GaN layer and a buffer layer. In order to analyze the mechanism for the N-based pretreatment, the details are measured by XPS analysis. It is found that the intensity of Ga-O bonds is decreasing and the intensity of Ga-N bonds is increasing, which means with the supplement of N, the dangling bonds on the surface are indeed reduced with the forming of Ga-N bonds, reducing the surface states. The surface states have a great influence on the leakage current, and improved surface states represent a better off-state of the device. After the N-based pretreatment, the breakdown voltage of the device with Lₛ𝒹=6 μm increased from 93V to 170V, which increased by 82.8%. Moreover, for HEMTs with Lₛ𝒹 of 6-μm, we can obtain a peak output power (Pout) of 12.79W/mm, power added efficiency (PAE) of 49.84% and a linear gain of 20.2 dB at 60V under 3.6GHz. Comparing the result with the reference 6-μm device, Pout is increased by 16.5%. Meanwhile, PAE and the linear gain also have a slight increase. The experimental results indicate that using N₂/NH₃ pretreatment before passivation is an attractive approach to achieving power performance enhancement.

Keywords: AlGaN/GaN HEMT, N-based pretreatment, output power, passivation

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Authors: Michael Daly

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Background/Aims: The interplay of childhood self-control and early life social background in predicting adult health is currently unclear. We drew on rich data from two large nationally representative cohort studies to test whether individual differences in childhood self-control may: (i) buffer the health impact of social disadvantage, (ii) act as a mediating pathway underlying the emergence of health disparities, or (iii) compensate for the health consequences of socioeconomic disadvantage across the lifespan. Methods: We examined data from over 25,000 participants from the British Cohort Study (BCS) and the National Child Development Study (NCDS). Child self-control was teacher-rated at age 10 in the BCS and ages 7/11 in the NCDS. The Early life social disadvantage was indexed using measures of parental education, occupational prestige, and housing characteristics (i.e. housing tenure, home crowding). A range of health outcomes was examined: the presence of chronic conditions, whether illnesses were limiting, physiological dysregulation (gauged by clinical indicators), mortality, and perceptions of pain, psychological distress, and general health. Results: Childhood self-control and social disadvantage predicted each measure of adult health, with similar strength on average. An examination of mediating factors showed that adult smoking, obesity, and socioeconomic status explained the majority of these linkages. There was no systematic evidence that self-control moderated the health consequences of early social disadvantage and limited evidence that self-control acted as a key pathway from disadvantage to later health. Conclusions: Childhood self-control predicts adult health and may compensate for early life social disadvantage by shaping adult health behaviour and social status.

Keywords: personality and health, social disadvantage, health psychology, life-course development

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Authors: Sharifullah Ahmed, P. Eng

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The Axle Pressure and the Consolidation Pressure decrease with the height of the highway embankment and the depth of subsoil. This reduction of pressure depends on the height and width of the embankment. The depth is defined as the significantly stressed zone at which the pressure is reduced to 0.2 or 20%. The axle pressure is reduced to 7% for embankment height 1-3m and to 0.7% for embankment height 4-12m at the bottom level of Highway Embankment. This observation implies that, the portion of axle pressure transferred to subsoil underlying the embankment is not significant for ESAL factor 4.8. The 70% consolidation to have occurred after the construction of the surface layer of pavement. Considering this ratio of post construction settlement, 70% consolidation pressure (Δσ70) is used in this analysis. The magnitude of influence depth or Significant Stressed Zone (Ds) had been obtained for the range of crest width (at the top level of the embankment) is kept between 5m and 50m and for the range of embankment height from 1.0m to 12.0m considering 70% of consolidation pressure (Δσ70). Significantly stressed zones (Ds) for 70% embankment pressure are found as 2-6.2He for embankment top width 5-50m.

Keywords: consolidation pressure, consolidation settlement, ESAL, highway embankment, HS 20-44, significant stressed zone, stress distribution

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Authors: Mizam Doğan

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Adapazarı railway car factory, the only railway car factory of Turkey, was constructed in 1950. It was a steel design and it had filled beam sections and truss beam systems. Columns were steel profiles and box sections. The factory was damaged heavily on Izmit Earthquake and closed. In this earthquake 90% of damaged structures are reinforced concrete, the others are %7 prefabricated and 3% steel construction. As can be seen in statistical data, damaged industrial buildings in this earthquake were generally reinforced concrete and prefabricated structures. Adapazari railway car factory is the greatest steel structure damaged in the earthquake. This factory has 95% of the total damaged steel structure area. In this paper; earthquake damages on beams and columns of the factory are studied by considering TS648 'Turkish Standard Building Code for Steel Structures' and also damaged connection elements as welds, rivets and bolts are examined. A model similar to the damaged system is made and high-stress zones are searched. These examinations, conclusions, suggestions are explained by damage photos and details.

Keywords: column-beam connection, seismic analysis, seismic load, steel structure

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Authors: Ebrahim Fataei, Seyed Ali Hosseini, Zahra Arabi, Habib farhadi, Mehdi Aalipour Erdi, Seiied Taghi Seiied Safavian

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Solid waste production is an integral part of human life and management of waste require full scientific approach and essential planning. The allocation of most management cost to collection and transportation and also the necessity of operational efficiency in this system, by limiting time consumption, and on the other hand optimum collection system and transportation is the base of waste design and management. This study was done to optimize the exits collection and transportation system of solid waste in Meshkinshahr city. So based on the analyzed data of municipal solid waste components in seven zones of Meshkinshahr city, and GIS software, applied to design storage place based on origin recycling and a route to collect and transport. It was attempted to represent an appropriate model to store, collect and transport municipal solid waste. The result shows that GIS can be applied to locate the waste container and determine a waste collection direction in an appropriate way.

Keywords: municipal solid waste management, transportation, optimizing, GIS, Iran

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Authors: Behnam Mahdiyan Nasl

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In a lab-scale research, the effects of feeding whey into the biogas system and how to solve the probable problems arising were analysed. In the study a semi-continuous glass reactor, having a total capacity of 13 liters and having a working capacity of 10 liters, was placed in an incubator, and the temperature was tried to be held at 38 °C. At first, the reactor was operated by adding 5 liters of animal manure and water with a ratio of 1/1. By passing time, the production rate of the gas reduced intensively that on the fourth day there was no production of gas and the system stopped working. In this condition, the pH was adjusted and by adding NaOH, it was increased from 5.4 to 7. On 48th day, the first gas measurement was done and an amount of 12.07 % of CH₄ was detected. After making buffer in the ambient, the number of bacteria existing in the cattle’s manure and contributing to the gas production was thought to be not adequate, and up to 20 % of its volume 2 liters of mud was added to the reactor. 7 days after adding the anaerobic mud, second gas measurement was carried out, and biogas including 43 % CH₄ was obtained. From the 61st day of the study, the cheese whey with the animal manure was started to be added with an amount of 40 mL per day. However, by passing time, the raising of the microorganisms existed in the whey (especially Ni and Co), the percent of methane in the biogas decreased. In fact, 2 weeks after adding PAS, the gas measurement was done and 36,97 % CH₄ was detected. 0,06 mL Ni-Co (to gain a concentration of 0.05 mg/L in the reactor’s mixture) solution was added to the system for 15 days. To find out the effect of the solution on archaea, 7 days after stopping addition of the solution, methane gas was found to have a 9,03 % increase and reach 46 %. Lastly, the effects of adding molasses to the reactor were investigated. The effects of its activity on the bacteria was analysed by adding 4 grams of it to the system. After adding molasses in 10 days, according to the last measurement, the amount of methane gas reached up to 49%.

Keywords: biogas, cheese whey, cattle manure, energy

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Authors: Vaclav Mentl, Josef Volak

Abstract:

In many industrial applications, materials are subjected to degradation of mechanical properties as a result of real service conditions, temperature, cyclic loading, humidity or other corrosive media, irradiation, their combination etc. The assessment of the remaining lifetime of components and structures is commonly based on correlated procedures including numerous destructive, non-destructive and mathematical techniques that should guarantee reasonably precise assessment of the current damage extent of materials in question and the remaining lifetime evaluation of the component under consideration. The answers to demands of customers to extend the lifetime of existing components beyond their original design life must be based on detailed assessment of the current degradation extent, what can be rarely realised by means of traditional mechanical (standardised) tests that need relatively large volumes of representative material for the test specimen manufacturing. This fact accelerated the research of miniaturised test specimen that can be sampled non-invasively from the component.

Keywords: small punch test, correlation, creep, mechanical properties

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Authors: M. Najafi

Abstract:

In the present paper, a large turbo-generator shaft train including a heavy-duty gas turbine engine, a coupling, and a generator is established. The method of analysis is based on finite element simplified model for lateral and torsional vibration calculation. The basic elements of rotor are the shafts and the disks which are represented as circular cross section flexible beams and rigid body elements, respectively. For more accurate results, the gyroscopic effect and bearing dynamics coefficients and function of rotation are taken into account, and for the influence of shear effect, rotor has been modeled in the form of Timoshenko beam. Lateral critical speeds, critical speed map, damped mode shapes, Campbell diagram, zones of instability, amplitudes, phase angles response due to synchronous forces of excitation and amplification factor are calculated. Also, in the present paper, the effect of imbalanced rotor and effects of changing in internal force and temperature are studied.

Keywords: rotor dynamic analysis, finite element method, shaft train, Campbell diagram

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Authors: Muhammad Hadi Ibrahim

Abstract:

The benefits of alternative/renewable fuels in general and a study of the environmental impacts of biofuels in particular have been reviewed in this paper. It is a known fact that, energy generation using fossil fuel produces many important pollutants including; nitrogen oxides, hydrocarbons, soot, dust, smoke and other particulate harmful matter. It’s believed that if carbon dioxide levels continue to increase drastically, the planet will become warmer and will most likely result in a variety of negative impacts including; sea-level rise, extreme and unpredictable weather events and an increased frequency of draughts in inland agricultural zones. Biofuels such as alcohols, biogas, etc. appear to be more viable alternatives, especially for use as fuels in diesel engines. The substitution of fossil fuel through increased utilization of biofuels produced in a sustainable manner, can contribute immensely towards a cleaner environment, reduction in greenhouse gas emissions and mitigation of climate change. Stakeholders in the energy sector can be sensitized by the findings of the research study and to consider the possible adverse effects in developing technologies for the production and combustion of biofuels.

Keywords: emission, energy, renewable/alternative fuel, environment, pollution

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Authors: Behrang Ekrami, Amin Tamadon

Abstract:

Caspian red deer or maral (Cervus elaphus maral) is a ruminant from the family of Cervidae. Maintenance and protection of maral requires knowing the behavioral, physiological, environmental characteristics and factors harmful to this species. In this article, reproductive and behavioral traits of this species in both sexes are presented based on observations and the available records of protected deer in Wildlife Refuge of Semeskande, Sari (one of the sites that preserve the maral in the Free Zones of Hyrcanian forest) from 2006 to 2011. Hart characteristics including sexual behavior, apparent changes during reproductive season and reproductive physiology; and hind characteristics including of ovulation, reproductive cycle, mating, pregnancy and parturition, have been evaluated. Identification of maral reproductive characteristics in Wildlife Refuge of Semeskande, Sari is one of the most important information requirements to preserve and breed this species and will open up new routes for performing new methods of reproduction of this species in Iran wildlife parks or other refuge areas.

Keywords: caspian red deer, reproduction, behavior, Iran

Procedia PDF Downloads 489

Authors: Muftah H. El-Naas, Ameera F. Mohammad, Mabruk I. Suleiman, Mohamed Al Musharfy, Ali H. Al-Marzouqi

Abstract:

CO₂ capture and storage technologies play a significant role in contributing to the control of climate change through the reduction of carbon dioxide emissions into the atmosphere. The present study evaluates and optimizes CO₂ capture through a process, where carbon dioxide is passed into pH adjusted high salinity water and reacted with sodium chloride to form a precipitate of sodium bicarbonate. This process is based on a modified Solvay process with higher CO₂ capture efficiency, higher sodium removal, and higher pH level without the use of ammonia. The process was tested in a bubble column semi-batch reactor and was optimized using response surface methodology (RSM). CO₂ capture efficiency and sodium removal were optimized in terms of major operating parameters based on four levels and variables in Central Composite Design (CCD). The operating parameters were gas flow rate (0.5–1.5 L/min), reactor temperature (10 to 50 ^oC), buffer concentration (0.2-2.6%) and water salinity (25-197 g NaCl/L). The experimental data were fitted to a second-order polynomial using multiple regression and analyzed using analysis of variance (ANOVA). The optimum values of the selected variables were obtained using response optimizer. The optimum conditions were tested experimentally using desalination reject brine with salinity ranging from 65,000 to 75,000 mg/L. The CO₂ capture efficiency in 180 min was 99% and the maximum sodium removal was 35%. The experimental and predicted values were within 95% confidence interval, which demonstrates that the developed model can successfully predict the capture efficiency and sodium removal using the modified Solvay method.

Keywords: CO2 capture, water desalination, Response Surface Methodology, bubble column reactor

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Authors: Muluken Z. Getie, Francois Lanzetta, Sylvie Begot, Bimrew T. Admassu

Abstract:

This study is aimed at the numerical analysis of the effects of phase angle and losses (shuttle heat loss and gas leakage to the crankcase) that could have an impact on the pressure and temperature of working fluid for a β-type Stirling cycle refrigerating machine. First, the developed numerical model incorporates into the ideal adiabatic analysis, the shuttle heat transfer (heat loss from compression space to expansion space), and gas leakage from the working space to the buffer space into the crankcase. The other losses that may not have a direct effect on the temperature and pressure of working fluid are simply incorporated in a simple analysis. The model is then validated by reversing the model to the engine model and compared with other literature results using (GPU-3) engine. After validating the model with other engine model and experiment results, analysis of the effect of phase angle, shuttle heat lose and gas leakage on temperature, pressure, and performance (power requirement, cooling capacity and coefficient of performance) of refrigerating machine considering the FEMTO 60 Stirling engine as a case study have been conducted. Shuttle heat loss has a greater effect on the temperature of working gas; gas leakage to the crankcase has more effect on the pressure of working spaces and hence both have a considerable impact on the performance of the Stirling cycle refrigerating machine. The optimum coefficient of performance exists between phase angles of 900-950, and optimum cooling capacity could be found between phase angles of 950-980.

Keywords: beta configuration, engine model, moderate cooling, stirling refrigerator, and validation

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Authors: Hecson Christian, Joel Macwan

Abstract:

Landfill site selection in an urban area is a critical issue in the planning process. With the growth of the urbanization, it has a mammoth impact on the economy, ecology, and environmental health of the region. Outsized amount of wastes are produced and the problem gets soared every day. Hence, selection of ideal site for sanitary landfill is a challenge for urban planners and solid waste managers. Disposal site is a function of many parameters. Among all, Geotechnical parameters are very vital as the same is related to surrounding open land. Moreover, the accessible safe and acceptable land is also scarce. Therefore, in this paper geotechnical parameters are used to develop a GIS model to identify an ideal location for landfill purpose. Metropolitan city of Surat is highly populated and fastest growing urban area in India. The research objectives are to conduct field experiments to collect data and to transfer the facts in GIS platform to evolve a model, to find ideal location. Planners’ preferences were obtained to use analytical hierarchical process (AHP) to find weights of each parameter. Integration of GIS and Multi-Criteria Decision Analysis (MCDA) techniques are applied to improve decision-making. It augments an environment for transformation and combination of geographical data and planners’ preferences. GIS performs deterministic overlay and buffer operations. MCDA methods evaluate alternatives based on the decision makers’ subjective values and priorities. Research results have shown many alternative locations. Economic analysis of selected site from actual operations point of view is not included in this research.

Keywords: GIS, AHP, MCDA, Geo-technical

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Authors: Thomas Ejobowah Boye, Philip Oghenetega Ekpon

Abstract:

The paper examines the availability and the utilization of recreational facilities for prison inmate’s rehabilitation in Nigeria. In order to carry out the study the researchers visited sampled prisons in the six geo-political zones in Nigeria. Instant assessment of available recreational facilities was carried out. Inmates were asked to tick a self-design questionnaire that was validated by experts in the Departments of Physical and Health Education, Delta State University and the College of Physical Education, Mosogar on available recreational facilities and activities engaged in by them. The data collected was subjected to percentage analysis. The study revealed that there is little or no standard recreational facilities in all the prisons visited. Considering the role physical activities play in the overall development of individuals physically, mentally, emotionally, morally, and socially it was recommended that the authorities of the Nigerian prisons should as a matter of urgency include recreational activities as a means of reforming and rehabilitating prison inmates. To achieve the desire to rehabilitate prison inmates the researchers also recommended that facilities and equipment should be made available in all prisons in Nigeria.

Keywords: facility, prison, recreation, rehabilitation

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Authors: Sayyed Yaghoub Zolfegharifar, Khairul Anuar Kassim, Hossein Khoramrooz, Khodayar Farhadiasl, Sadegh Jahan

Abstract:

Iran is one of the world's seismically active countries so that it experiences many small to medium earthquakes annually and a large earthquake every ten years. Due to seism tectonic conditions and special geographical and climatic position, Iran has the potential to create numerous severe earthquakes. Therefore, seismicity studies and seismic zonation of seismic zones of the country are necessary. In this article, the effect of local site conditions on the characteristics of seismic design in Rahmormoz will be examined. After analyzing the seismic hazard for Rahmormoz through deterministic and statistical methods and preparing the necessary geotechnical models based on available data, the ground response will be analyzed for different parts of the city based on four inputs and acceleration level estimated for bedrock through the equivalent linear method and by means of Deep Soil program. Finally, through the analysis of the obtained results, the seismic profiles of the ground surface for different parts of the city will be presented.

Keywords: seismic microzonation, ground response, resonance spectrum, period, site conditions

Procedia PDF Downloads 346